FuelNet is a generic computer code to predict flow transient dynamics in the fuel delivery systems. It employs modal approximation to simulate wave dynamics in fuel lines. This modal approximation provides the accuracy comparable to the quasi-method of characteristics, which is one step more accurate than the standard method of characteristics. The bond graph approach is used to ensure the whole fuel delivery system is properly connected and the input/output causalities are matched at the junctions and interfaces. All the ordinary differential equations are integrated in the time-domain by the Runge-Kutta method to obtain the pressure and the flow rate.FuelNet takes into account the hydraulic effects of the fuel injector, the pressure regulator, the fuel pump, and the pulse damper, as well as the operating conditions such as the engine speed, the injector pulse width, the injector firing strategy and sequence, and the PID controls. Typical FuelNet outputs are time-histories of pressure and flow rate.